 |
 |
 |
|
|
WP-2: Establishing of database structure and submodel development in the Neckar basin Objectives
Description of work The Neckar basin is with the region with the highest data density. Therefore, the Neckar basin is used to develop and adjust the submodels and the integrated model MOSDEL II. In the first place, a database about the water resources is established. Information about geology, relief, hydraulic properties, groundwater quality, groundwater levels, groundwater extraction from wells, artificial recharge and natural groundwater recharge, river discharges, water reservoir levels and surface water quality is needed. This information will be collected from all possible sources and transferred into a uniform digital format. A GIS environment will be used to store, organize, analyze and visualize the data. Data collection will be carried out in close cooperation with the local governmental authorities, research institutes and consultants, mainly provided by the water authorities of the federal state Baden-Wurttemberg (BW), namely the Landesanstalt fur Umweltschutz (LfU) and the Gewasserdirektion Neckar. A database including GIS related information and time series data of the relevant water uses is established for RB1. The data include the temporal variability of the demand , its spatial pattern, the sensitive ecological regions together with its minimal requirements with respect to water quantity and quality, and the economic aspects of water supply and waste water treatment. For an efficient application of hydrological models on that scale (14 000 km2) a preprocessor based on ArcGIS and ACCESS will be developed that allows fast delineation of subcatchments, grid cells, the coupling to a drainage network and the assignment of model parameters to the grid cells. Water quality data i.e. nutrient and heavy metal immission from different sources will be provided by the LfU based on the MONERIS Baden-Wurttemberg and will be processed with the preprocessor to provide necessary input data for the water quality submodel. Burning surface water management issues in the Neckar basins are floods, but also drinking water supply. In cooperation with the LfU and the “Gewasserdirektion Neckar” analyze impact of climate and landuse change scenarios on floods and fresh water supply to develop integrated strategies to cope with these possible scenarios. (2B). The surface water models HBV-IWS/LARSIM model will be adopted to the Neckar basin using an advanced parameter estimation approach that links available data on catchment characteristics to the model parameters. For water pollutant input estimation, the model MONERIS (Behrendt et al. 1999) will be used for point sources and the output of the SLYSIS model for non-point sources from agriculture. The implementation of the model will require modifications of the numerical schemes in order to adapt the model to different climatic conditions. For the riverine water quality simulation above the fall line/salt wedge the model QUALIE (U.S. EPA 600/3-87/007) and different numerical modules developed by participant No. 4 will be tested. For lake water quality estimation, the lake and estuary water quality simulator WASP (U.S. EPA 600/3-87/039) will be coupled to a 3-D hydrodynamic model. Information from the databases will be used to set up a conceptual geohydrogeological model of the Neckar. The development of a basin-wide three-dimensional finite difference (FD) groundwater flow (MODFLOW) and simplified transport models (Particle tracking e.g. MODPATH; Nitrate and Chloride) is possible. The numerical model will be calibrated for steady state conditions and finally validated using field data (transient). In order to study the influence of scaling issues and data availability, different grid resolutions (500 by 500 m to 5000 by 5000 m cell size) and aquifer numbers will be chosen to discretize the model domain. The groundwater model will be coupled with the hydrological model (HBV, LARSIM) using the MODFLOW “river” and “recharge” packages. Percolation and water level in rivers calculated by HBV (with postprocessing to calculate river levels asl / per cell) will be used as input data to determine the in-/exfiltration from rivers to the groundwater and the natural groundwater recharge. A further aim is the development of a mesoscale habitat simulation model based on the available model CASIMIR (Computer Aided Simulation Model for Instream Flow Requirements) and its extension considering water quality parameters. This model can be used for the assessment of the ecological status of anthropogenic modified water bodies. It is an instrument for the identification of the major impacts and the development of rehabilitation measures. The simulation is based on information on river geometry and morphology, hydrology and networking (i.e. migration). The linkage to ecology is performed by habitat demands of target species. As a prerequisite for sustainable water management a description of the spatio-temporal pattern of the water resources availability in terms of quantity and quality has to be established. Sensitive ecological zones need to be identified and the interdependences with the water system have to be analysed. The major users (domestic, industrial, agricultural, tourism and recreation, ecological requirements) are characterised by their temporal water demand, their technological level, their contribution to local and regional economy and employment, and their environmental impacts due to water use. Part of this work is already done in other modules like GAMS, SLISYS. The costs for water supply, waste water treatment are estimated and based on existing water prices an economically based evaluation is carried out. The impacts of water abstraction and waste water effluents on the surface and groundwater system are modelled by subsequent modules. Different scenarios considering modified land use, technological improvement in efficient water use and in waste water treatment, and various levels of population growth are run for each river basin. Finally a sensitivity analysis will help to quantify the importance of the various uncertainties in the scenarios and in the model parameters. The work is mainly based on the WEAP-21 model. Crop yields, soil water and solute dynamics as well as ground-water formation in agricultural areas are simulated using the EPIC model. Further information obtained are nutrients (NO3, phosphate), organic material in suspension, plant protection products and biocides and sediment discharges and crop yield output. The model will be validated at representative sites in the Neckar basin and the uncertainties of model results at the field scale quantified. The results of this model are compared and harmonized with the mesoscale hydrological model. The land resource information system SLISYS will be used to upscale the results of the crop model. It consists of a soil and climate database that follows the SOTER approach (Soil and terrain digital database) recommended by FAO. CORINE data as well as additional satellite images (LANDSAT TM) from the river basin will be classified and interpreted to produce land use/cover maps for different vegetation periods. The existing agroecomomic model of the Danube basin ist described in a number of publications (Dabbert et al. 2002, Rohm and Dabbert 2003). A non-linear programming model using positive mathematical programming techniques of the agricultural sector is linked to an aggregation and disaggregation tool that is able to downscale economic reults to the spatial resolution required as input for the models of the natural sciences. The agricultural sector model includes specifically water use by agriculture. In terms of disciplinary innovation the project seeks to develop methods for relatively easy implementation of the existing regional model of agricultural production of the upper Danube catchment to other catchments. The objective is thus to develop a more generic way of model with good transferability to other cases. Right from the beginning a database structure for an overall project database for the all three basins, including the Neckar basin, will be ready to use for all project partners. Basic parameters of general concern will be stored centrally for the whole project (mainly physical and administrative data), while disciplinary databases will be left in responsibility of each working group. At the beginning the database will serve mainly basic needs of each working group and especially of the integrated model. Therefore a minimum number of variables will be defined by content, time and space. It will be later on adapted to the requirements of potential users, e.g. public authorities. As variables of database will be discussed intensively with the project community, this will be a catalytic factor to reach broad awareness for integration needs. Input data will be surveyed by the river basin groups. The central database service includes a plausibility and consistency check. Thus, important outlines for transferability of the models to the different river baisns will be assured. The database will inlude a set of basic maps. Numeric data will be inserted in the GIS database. The resolution of grid cells of 1 km2 is proposed for all regions. Graphical user interfaces will be designed for remote queries (internet) All submodels will be used for (a) the quantification of landuse change impact on the surface water dynamics, originating from the economic scenarios as well as b) the quantification of parameter uncertainty originating from uncertain catchment data incl. rainfall. For models testing and validation a risk and reliability analysis will be developed. Uncertainties are due to limited information on the values of physical parameters and input data. In order to quantify such uncertainties physical coefficients and input parameters will be represented as fuzzy numbers. By combining representation of fuzzy numbers as a discrete set of h-level cuts with reliable numerical algorithms and applying the extension principle, reliable fuzzy numerical simulations will be obtained (Ganoulis et al. 1996). Deliverables
Milestones and expected results
|
Designed by |
 |